The original strain mRNA vaccines generated B cells that could bind the original strain and three variants that followed, per the pre-Omicron paper below. And a booster with an mRNA vaccine enhanced this cross-reactivity, providing "potent neutralization of Omicron" per the post-Omicron paper even further below.Woodchopper wrote: ↑Thu Dec 23, 2021 7:29 pmAs for vaccines having primed people immune systems to work against other variants, that is likely.
https://www.science.org/doi/10.1126/science.abm0829
https://www.medrxiv.org/content/10.1101 ... 21267755v1mRNA vaccination also generated spike- and RBD-specific memory B cells, including memory B cells that cross-bound Alpha, Beta, and Delta RBDs, that were capable of rapidly producing functional antibodies after stimulation ... also generated a higher frequency of variant cross-binding memory B cells than mild SARS-CoV-2 infection alone, with >50% of RBD-specific memory B cells cross-binding all three VOCs at 6 months. These variant-binding memory B cells were more hypermutated than wild-type–only binding cells
Nice image here that shows the booster dose restoring neutralization against wild-type virus to previous levels and getting neutralization against Delta & Omicron to higher levels than ever. https://www.medrxiv.org/content/medrxiv ... .large.jpgRemarkably, neutralization of Omicron was undetectable in most vaccinated individuals. However, individuals boosted with mRNA vaccines exhibited potent neutralization of Omicron only 4-6-fold lower than wild type, suggesting that boosters enhance the cross-reactivity of neutralizing antibody responses.